Process of modifying cellulosic materials with ionizing radiation



United States Patent 3,254 939 PROCESS OF MODIFYINE CELLULOSIC MATE- RIALS WITH IUNIZING RADIATION Fritz Munzel, Schwerzenbach, Switzerland, assignor, by

mesne assignments, to Herberlein & Co. AG., a corporation of New York No Drawing. Continuation of application Ser. No. 125,088, July 19, 1961. This application Feb. 1, 1965, Ser. No. 429,617

28 Claims. (Cl. 8--116) This application is a continuation-in-part of application S.N. 30,056, filed May 17, 1960, and now abandoned; a continuation-in-part of application S.N. 111,900, filed May 23, 1961; and a continuation of application S.N. 125,088, filed July 19, 1961.

This invention relates to improved cellulosic textile products and to new methods for finishing cellulosic textiles to improve certain of their physical characteristics, and more particularly it relates to irradiated cellulosic textile materials of improved crease resistance, tearing strength, and abrasion resistance and to a method facilitating the action of ionizing radiation upon the cellulosic textile material to produce a vastly improved cellulosic textile product.

For purposes of this application the term textile material as employed herein shall be understood to include textiles of all kinds, including fibers, yarns, threads, and more manner of knit or woven fabrics, as well as nonwoven or felted fabrics. Further, for purposes of this application the terms cellulosic textile material and cellulosic textile sheet material shall be understood to include sheets or films of regenerated cellulose in fabrics of all kinds, whether woven, knit, felted or non-woven, which fabrics consist entirely of natural and/or regenerated cellulose and mixtures thereof as well as all manner of knit or woven fabrics, films, or sheets in which the cellulosic constituents constitute a major portion and noncellulosic constituents make up the remaining minor portion thereof. Generally for purposes of simplicity, the present invention is described with reference to cotton fabrics, and in certain of its aspects as hereinafter indicated is primarily directed to the finishing of cotton, rayon, or mixed cotton and rayon fabrics.

Attempts have been under way for some time to achieve improvements in cellulosic textiles through the use of ionizing radiation, but it has been noted that radiation of this type causes a change in the physical structure of the cellulose polymer molecule similar to a chemical decomposition. For example, in tests conducted with cellulosic textiles it was found that a relatively large dose of ionizing radiation causes a very great reduction in the degree of polymerization of the cellulose, and to all intents and purposes destroys the utility of the textile. With small doses of irradiation there was found to be no appreciable increase in the physical properties of the textile.

According to application Serial No. 30,056, it was found that the physical properties of cellulosic textile materials could be substantially improved with the aid of ionizing radiation under certain conditions of textile moisture, followed by heating where irradiation was carried out in the presence of oxygen. In that application it is pointed out that at conditions of about 20 to 50% moisture in the cellulosic textile ionizing radiation and subsequent heating effect substantial improvement in the physical properties of the textile as a result of cross-linking of the cellulosic molecule. The favorable results obtained by the process of application Serial No. 30,056 are believed from a radiation chemical standpoint to be due to the fact that during irradiation of the cellulosic textile under the above moisture conditions, which approximate the range of maximum swelling of the cellulose, substantially more activeions are formed from the water present than are formed on the cellulose molecule, and that these excited ion species can transfer their energy to the cotton molecule, and in fact very likely react with excited centers on the cellulose causing cross-linking.

The present invention constittues a substantial improvement over the process of application Serial No. 30,056, in that cross-linking may now be very easily effected, with resulting substantial improvement in the physical properties of the cellulosic textile material, without resort to irradiation of the cellulose in water-swelled condition or at a critical moisture content. Furthermore, in the present process it is no longer necessary to apply heat to the cellulosic textile during or following irradiation.

In accordance with the method of the present invention it has now been found that cross-linking may be achieved to a desired degree and the physical characteristics of the cellulosic textile thereby very substantially enhanced when the textile is subjected to ionizing radiation in the presence of certain chemical substances hereinafter termed sensitizers in contact with the textile which contains molecular groups, presumably ionizable atoms, capable of absorbing the radiation energy to an extent that they are excited to oscillate or resonate and so transfer or transmit excitation energy to the electrons of the atom or atoms of the cellulosic molecule which enterinto the cross-linking reaction thus facilitating the establishment of a crosslinking between the cellulosic polymers. Furthermore, in the present process subsequent heating of the irradiated material is not required. Also, upon treatment with the sensitizer the cellulosic textile material may be irradiated at ambient moisture conditions, which are generally between about 1 and 10% depending upon conditions of humidity in the finishing plant.

While the above explanation as to the manner of functioning of the sensitizer is believed to be correct, it is a fact'that regardless of the phenomena involved cellulosic textile materials to which the sensitizer has been applied prior to irradiation are in a condition which is more advantageous for receiving ionizing radiation energy than textiles irradiated in the absence of the sensitizer.

It is well known that cellulosic fabrics, particularly cotton fabrics, become capable of recovering in a short time after creasing in a dry condition if they have been treated with the well-known finishing resin precondensates, for example methylol precondensates with urea and urea derivative or melamine precondensates. The precondensate penetrates the cellulose fibers of the fabric and is converted to an insoluble resin by polycondensation when heated in the presence of a catalyst. However, these conventional resin-finishing techniques do not appreciably enhance the ability of the finished fabrics, as compared with the starting fabrics, to recover from creases imparted during washing or when the fabric is in a wet condition. While such conventionally finished textile materials maybe considered crease-resistant so long as the creases are imparted to the fabric while it is dry, they often do not exhibit entirely satisfactory wet-crease resistance, which resistance is the criterion of the wash-and-wear properties of a fabric.

Therefore in accordance with another aspect of the present invention it has been discovered that excellent wet crease resistance, as well as dry crease resistance and improved strength, can be imparted to the cellulosic textile material if it is first treated with a radiation sensitizer as indicated above and subsequently at least one graftable organic finishing chemical is grafted onto the cellulosic molecule.

.In a related application, S. N. 147,380, filed on July 19, 1961, there is described a process for improving mechanical properties of a cellulosic textile material by first subjecting the unfinished textile toionizing radiation of a critical total dose and then applying a condensible or resin-forming material to the textile which condenses thereon. In accordance with that process, heat is not required to condense the resin-forming substances as in conventional prior art finishing techniques.

According to the aspect of this invention involving subsequent treatment with a graftable organic finishing chemical, the cellulosictextile material is subjected to ionizing radiation of a critical dose between about 5x10 and 3 l0 rad in the presence of the radiation sensitizer, and the graftable organic finishing chemicalis applied to the fabric and grafted thereon. More specifically, the cellulosic textile is first treated with the radiation sensitizer, then irradiated and then subsequently at least one graftable organic finishing chemical is applied thereto, preferably (although not necessarily) at an elevated temperature between about 40 and 100 C. In some instances, particularly where the graftable chemical is dissolved or dispersed in aqueous media, the graftable chemical may be applied to the cellulosic textile during irradiation. For example, the cellulosic textile may be irradiated while immersed in or wetted with a solution or dispersion of the graftable chemical. The graftable organic finishing material may be a polymerizable monomer, an unpolymerizable chemical or an already polymerized substance. The term nonpolymerizable asemployed herein is intended to designate chemicals of the latter two categories, namely, already polymerized materials and chemicals which are incapable of polymerization.

Surprisingly it has been found that some cellulosic fabrics cannot be cross-linked and thus improved even under the most favorable conditions of moisture as set forth in application Serial No. 30,056, presumably because the textile contains small quantites of metal soaps which cannot be removed. When such fabrics are treated in accordance with the method of the present invention cross-linking is easily effected and the desired physical improvements realized.

By reason of the high efficiency of the sensitizer desired improvement of the physical characteristics of the textile maybe obtained at substantially lower radiation doses. Accordingly, degradation of the cellulosic molecule as a result of having been subjected to ionizing radiation is very significantly reduced.

The sensitizers useful for carrying out the process of the present invention comprise both organic and inorganic materials which possess in common the ability to absorb ionizing radiation energy and transfer excitation energy to the cellulose molecule.

The inorganic sensitizers comprise heavy metal oxides and inorganic salts and heavy metal salts of organic acids containing about 1 to 4 carbon atoms. Suitable materials are, for example, the oxides or salts of titanium, chromium, zinc, tungsten, osmium, thorium, and uranium.

Organic sensitizers include certain unsaturated aliphatic compounds and aromatic compounds containing about 1 to 6 benzene rings. The suitable aliphatic compounds are olefinic and contain 4 to 20 carbon atoms in the aliphatic chain as well as l to 3 olefinic unsaturations. 'The unsaturated linkages, i.e. carbon-carbon double bonds, may be either conjugated or isolated from one another, but in the latter case the unsaturations are separated by at least two carbon atoms. These aliphatic olefinic sensitizers may be either hydrocarbons, aldehydes, suchas crotonaldehyde or citral, ketones, or primary or secondary amines.

The aromatic compounds suitable as sensitizers in the present process are those containing up to about 6 benzene rings, and preferably those containing 2 or 3 condensed or uncondensed benzene rings. Typical uncondensed ring compounds include the diphenylbenzenes, diand triphenyl methane, polyphenylethanes, fluorene and benzal fiuorenes. Compounds of this type containing two or three uncondensed rings are very effective.

4, A particularly preferred sensitizer of this type is 1,4- diphenylbenzene.

Further typical aromatic compounds suitable as sensitizers include ketones and primary and secondary amines. Representative ketones of the 2 and 3 condensed and uncondensed ring types include quin-one, naphthoquinones, benzoylfiuorenes, benzil, benzalacetophenone, dicyannamylideneacetone, diphenoq-uinone and hydroxyacetophenone. Two particularly preferred sensitizers of this latter class are m-naphthoquinone (1,4-diketo-2,3-dihydro-naphthalene) and benzophenone. Of the aforementioned aromatic amines, those consisting of three condensed benzene rings with one to three amino groups on said rings are especially preferred. Examples of such amines are aniline, diphenylamine, tributylamine, cyclohexylamine.

The sensitizers are effective in the present process when present, in contact with the cellulosic textile material being irradiated, in exceedingly small quantities. For example, the sensitizers perform eminently satisfactorily when present on the textile in amounts insufficient :to change the external appearance of the goods.

The sensitizer is applied to the cellulosic textile before irradiation. Application of the sensitizer to the fabric is preferably from an aqueous solution, dispersion or emulsion in order that the cellulosic molecule may swell in the presence of water which permits uniform and complete deposition of the sensitizer. Since such small quantities of the sensitizer are effective in the present process the aqueous solution or dispersion may be very dilute, for example between about 0.1 and about 5%.

Following application of the sensitizer, the textile material is subjected to ionizing radiation to a total dose between about 10 and 10 rad. As noted above crosslinking is now more efficiently realized than heretofore and the irradiation dose may be lower than required in other earlier processes. Accordingly, the preferred irradiation dose is between 10 and 10 rad. It has been found that cellulosic textiles which had previously required doses in excess of 10 rad to effect substantial cross-linking in the presence of 20-60% water can in many instances now 'be cross-linked to a greater extent, resulting in further improved physical characteristics, in accordance with the present process at doses ranging from about 10 rad to not above about 10 rad. This fact is particularly important in the treatment of certain of the regenerated celluloses, which are considerably more sensitive to ionizing radiation with resulting decomposition than is cotton.

The ionizing radiation may be electromagnetic in character, as roentgen or gamma rays, the latter being permitted by cobalt, cesium burnt uranium slugs, or the fission products of uranium Beta rays having a particle energy between about 0.05 and l mev., as produced by the usual electronic accelerators such as the cascade, Van de Graaff, or linear accelerators are also satisfactory, as are the beta particles derived from radioactive materials such as strontium Generally speaking the irradiation time to reach the aforementioned total dose will vary between 10 seconds and 4 hours, depending upon the desired total dose and the quality of the source.

The process of the. present invention is applicable to both heavy and light-weight cellulosic textile materials. It is particularly well adapted to the improvement of crease resistance, wash and wear properties, tearing strength and abrasion resistance of organdies and parchmentized fabrics as well as mercerized or bleached goods.

The process is also applicable to the treatment of cellulosic textile materials, especially fabrics, which have been previously subjected to conventional resin finishing to improve crease resistance. and dimensional stability, and the conventionally finished wash and wear cotton or mixed cotton and artificial fiber fabric may be further substantially improved in accordance with the present invention. Conventional wash and wear finishing referred to is achieved by applying to the cotton textile a condensible resin, for example methylol ureas, methylol amines, condensates of formaldehyde with phenol and phenol derivatives, ketone-aldehyde precondensates, aziridinyl compounds, diglycide ethers. Other suitable resin-forming substances are N-substituted urea formaldehyde resin compositions such as ethylene urea, dioxy ethylene urea or N,N'-bis (methoxymethyl) uron and tetrahydro-1,3-bis (methoxymethyl)-5-methyl-2(l) s triazone. A typical finish is dihydroxymethylurea in the presence of a zinc nitrate condensation catalyst. Following application of the resin precondensate the fabric must be heated to temperatures above 100 C. for a period of time in order to affect condensation of the resin. Crease-resistance is thereby improved, but fiber strength is very substantially reduced by the resinfinish, and as a result the tensile or tearing strength of the goods as well as their abrasion resistance is appreciably lowered. Surprisingly, when this conventionally treated textile is subjected to the process of the present invention tearing strength and abrasion resistance are very greatly increased, as is also the crease resistance.

The present invention is further illustrated by the following examples:

Example I A cotton poplin fabric was treated at 20 C. in a water bath containing approximately 1% by weight 1,4-diphenylbenzene, after which it was subsequently dried at about 6070 C. It was then irradiated at an ambient moisture content of about 8% to a total dose of rad from a cobalt source. The resulting fabric was insoluble in cuprammonium solution. The tensile strength of the fabric was measured in warp and fill directions with a Schopper pendulum apparatus on strips 2.5 cm. wide. Abrasion resistance was measured with a standard testing apparatus having a disc covered with a standardized wool cloth which was rotated on the surface of the fabric until the fabric failed, and the number of revolutions to failure was noted. Crease resistance was also determined, as evidence by crease angles in warp and fill directions. These angles were determined as follows: Strips of the fabric 3 x 5 cm. were conditioned for 24 hours at 21 C. and 65% R.H., and thereupon folded and placed under a 1 kg. weight for one hour. Upon removal of the weight, the fabric samples were left unweighted for fifteen minutes and the crease angle was measured. The values for crease angle, tensile strength and abrasive strength were as follows:

Example II An untreated piece of cotton imitation poplin fabric which could not be successfully cross-linked by simple irradiation at a moisture content of 30-40%, presumably because of the presence of very small quantities of adhering metal soaps, was treated as set forth in Example I with the 1,4-diphenylbenzene solution, and then dried to a moisture content of about 9%. It was subsequently exposed to cobalt to a total dose of 9 l0 rad. The resulting fabric was insoluble in cuprammonium solution and the following table compares its properties with those of the starting material, including the degree of polymerization of the cellulose:

Crease Angle Tearing Strength Abrasive Strength Warp Fill Warp Fill Starting material 40 45 18. 6 12 13, 400 Irradiated material 110 114 20 12. 3 40, 500

Example III Crease Angle Y Tearing Strength (g.) Abrasive Strength Warp Fill Warp Fill Starting material, 60 46 644 540 14, 350 I S0 924 844 19, 063 II 105 934 996 25, 436

Tearing strength was measured with a pendulum apparatus, specifically an Elmendorf tearing tester, on strips of a width of 6.3 cm. and a length of 16.5 cm.

Example IV A cotton voile was treated in a bath containing 1,4- diphenylbenzene and dried as described in Example I. A section (I) of the starting material and a section (II) of the treated fabric, both having moisture contents of about 10% were subsequently subjected to electron radiation of a particle energy of 0.08 mev. to a total dose of 2x 10 rad. The properties of the fabrics were as follows:

Crease Angle Tearing Strength Abrasive Strength Warp Fill Warp Fill Starting material 73 62 1, 056 1, 058 7, 870 I 66 72 767 912 10, 800 118 120 2, 510 2, 730 30, 600

Example V A mercerized bleached cotton muslin was parchmentized with sulphuric acid of 52 B. at 15 C. for a period of 16 seconds, subsequently remercerized, washed until neutral and dried. The resulting fabric was transparent. A section (I) of the parchmentized fabric, and another sect-ion (II) of the parchmentized fabric which had been treated with the solution of Example I, and then dried to about 10% moisture, were subjected to electron radiation of a particle energy of 0.12 mev. to a total dose of 2 x 10 rad. The properties of the fabrics were as follows:

Crease Angle Tearing Strength Abrasive Strength Warp Fill Warp Fill Starting material 7 8 312 1, 650 40 45 295 564 3, 270 100 95 520 .540 3, 780

7 Example VI Several portions of a cotton imitation poplin fabric were treated with 1% solutions or dispersions of several metal compounds and benzophenone, after which they were dried to a moisture content of about 10%. All sections were then subjected to a cobalt source to a total dose of 1-0 rad. The properties for the starting and resulting fabrics were as follows:

Example VII Several sections of a cotton muslin fabric were treated with 1% solutions or dispersions of tungsten oxide, zinc oxide and benziophen'one, respectively, dried to a moisture content of about 10% and subsequently subjected to a cobalt source to a total dose of 10 rad. The propertiesof the starting and resulting fabrics were as follows:

Crease Angle Tearing Strength Abrasive Compound Strength Warp Fill Warp Fill Starting material 8 280 225 2, 840 Tunsgteu dioxide 80 85 660 700 5, 400 Zinc oxide 85 100 500 500 6, 720 Benzophenone 75 80 540 380 5, 300

I Example VIII Crease Angle Tearing Strength Abrasive Compound Strength Warp 7 Fill Warp Fill Starting material 43 46 680 590 16, 500 I (gamma) 135 130 1, 580 1, 570 28, 300 II (beta) 145 140 1,775 1,800 62,300

It will be noted that the beta-irradiated material is superior to the section which was subjected to gamma radiation, even though the total doses were the same.

Example IX A cotton imitation poplin fabric was treated in the conventional manner to impart crease resistance or wash and wear properties thereto by impregnating with a solution containing 110 g. of dimethylurea dissolved in 1 liter of water, which also contained 11 g. of zinc nitrate con densation catalyst. It was thereupon squeezed and dried at 60-70 C., subsequently heated to 140- C. for four minutes to condense the resin and then washed and dried. -A section (I) of the thus treated fabric and a second section (II), which latter was treated in a bath containing 1% 1,4-diphenylbenzene and dried as described in Example I, were subjected at fabric moisture contents of about 8 810% to a cobalt source to a total dose of 10 rad. The properties of the resin-finished starting material, the irradiated resin-finished starting material (I) and the sensitizer-treated irradiated resin-finished material (11) exhibited the following properties:

Crease Angle Tearing Strength Abrasive Compound Strength Warp Fill Warp Fill Resin-finished starting material 40 650 580 14, 250 I 110 105 260 230 10, 530 II 105 110 1, 120 1, 050 32, 750

The products of the present invention are thus ionizing radiation-finished cellulosic textile materials of improved crease resistance, wash and wear properties, tearing strength and abrasion resistance as compared with the starting material. The starting material may be in the form of previously unfinished or already conventional resin-finished parchmentized or otherwise preliminary finished cellulosic materials.

According to the aspect of this invention wherein a graftable organic finishing chemical is applied to the mate rial after irradiation, said finishing chemical is applied to the cellulosic material during or following irradiation from aqueous or organic solutions or dispersions, as is customary in the-conventional textile finishing art. As gr-aftable polymerizable polymers there may be employed unsaturated compounds, more particularly vinyl or allyl compounds, such as acrylamide, acrylates, methacrylates, styrene, vinyl acetate, vinyl chloride, or vinylidine chloride, or one of the ethylenically unsaturated monomers, for example ethylene, tetrafiuoroethylene, butadiene or isoprene, or the like. Among the non-polymerizable graftable chemicals are those materials which are incapable of polymerization as well as already polymerized materials, including higher alcohols, aldehydes, ketones, sulfones, acetals, halogenated compounds, amines, ethers, esters, phenols, ethylene polymers, and vinyl and acrylic polymers. v

The use of low energy accelerated electrons forms an important part of this aspect of the present invention. The importance of low energy particles (below about 1 mev.) is described in related application S.N. 125,089, filed July 19, 1961. Therein it is pointed out that the degradation of the cellulosic molecule of the textile is greatly reduced when low energy particles are employed.

Where accelerated electrons are employed as the source of ionizing radiation, the accelerator is so arranged with respect to the surface of the cellulosic textile material that the stream of electrons (beta particles) is directed at an acute angle thereto. Their passage into and through the textile material is thus oblique and the particles describe a slightly longer path in the material, which results in improved irradiation efliciency. Good results are achieved if the total ionizing radiation imparted to the textile whether electromagnetic or beta radiation, is to a dose range of about 5x10 to 3X10 rad, preferably about 2 to 7X10 rad. Within this dose range degradation of the cellulosic molecule of the textile is at a minimum consistent with the very substantially increased wet and dry crease resistance and increase in the physical properties of the textile material. With low energy accelerated electrons and the aforementioned dose range there is virtually no deterioration of the cellulose.

The method of the present invention will be further apparent from the following typical examples, employing various graftable organic chemicals, which illustrate practical applications of the present method and set forth the 9 Example X A cotton poplin fabric was treated at 20 C. in an aqueous bath containing about 1% 1,4-dipheny1benzene and thereupon dried at 60-70 C. Several sections, A through 10 X. Several sections, A through F, were thereupon subjected to gamma radiation from a C source for different times to achieve different total doses. The sections were then treated with an aqueous solution containing F were bj d to gamma radiation f a C060 Source by weight of divinyl sulfone with the aid of a foular'd for different times in order to impart diflerent total doses. at Washed out, and the Wet crease angle r- The irradiated fabric sections were then treated with the mllled- The Sections Were then dried and the y Crease aid of a foulard with an aqueous solution containing 5% g tearing Strength and abrasive Strengths Were measby weight of acrylamide at 90 C., washed out and the sured. The results are shown in the following table:

Starting A B G D E F Material Irradiation Time (hours) 1 1 2 3 4 5 Irradiated Dose (rad) 1. x10 2. 5x10 5x10 15x10 10 1. 25x10 Wet Crease Angle (degrees):

Warp 00 125 143 140 110 95 F 65 130 145 142 110 96 Dry Crease Angle (degrees):

Warp 45 110 125 110 115 Fill 40 96 115 123 110 120 Tearing Strength (g.):

War 500 1,105 1,410 1,290 1,050 F111 540 1,100 1, 350 1, 305 1,020 Abrasive Strength 1 12, 310 24, 830 29, 330 31,310 22,810

1 In number of revolutions.

wet crease angle measured. The sections were then dried 30 From Examples X and XI it will be apparent that with at about 60 C. and the dry crease angle, tearing strength the particular fabric and the particular graftable chemiand abrasive strength were then measured. The following cal employed very superior wet and dry crease angles as table illustrates the dose of ionizing radiation to which well as superior tearing and abrasive strengths are obeach'of the sections was subjected and the improved retained at doses between about 2.5 10 and 5X10 rad. sults obtained as compared with the starting material. 35 Attention is particularly directed to the very substantially Example XII improved wet crease angle. A cotton poplin fabric was treated with a 1% aqueous Starting A B c D E F Material Irradiation Time (hours) 1 2 3 4 5 Irradiated Dose (rad).-- 1. 25x10 2. 5X105 5x10 7. 5X105 10 1. 25 10 Wet Crease Angle:

War 60 139 151 142 142 100 Fill 65 140 160 145 145 110 100 Dry Crease Angle (degrees):

War 45 95 119 125 40 90 120 Tearing Strength (g.):

Fill 540 1, 300 1, 505 1, 550

Abrasive Strength 12,310 32, 320 40,810 42,350

1 In number of revolutions.

Results equivalent to those set forth in the above table solution of 1,4-diphenylbenzene as described in Example were obtained by substituting 1,4-na-phthoquinone for the X, and thereupon subjected to gamma radiation from a 1,4-diphenylbenzene. 55 Co source to a total dose of 25x10 rad. The fabric Crease angles were determined with wet and dry secwas subsequently treated with an aqueous solution containtions as follows: 3 x 5 cm. strips of the starting and ing 5% by weight of nonyl alcohol at 90 C. with the aid treated fabric were folded in the warp or fill direction of a foulard. The wet crease angle was measured, and

- respectively and placed under a weight of 1 kg. for one the fabric was then dried and dry crease angle, tearing and hour. Following removal of the weight the materials 60 abrasive strengths were determined. The results were as were left unweighted for 15 minutes and the crease angle follows: was thereupon measured.

Tearing strength was determined with an Elmendorf Tearing Tester, as described in the ASTM-Standards on Textiles of the American Society for Testing Materials, 65 Startihg Irradiated 1956 Edition, pages 250-254, on strips having a width of Material Fabric 6.3 cm. and a length of 16.5 cm. Abrasive strength was measured with a testing apparatus having a disc covered gradr'atlongnne (hours) 1 with a standardized wool cloth which was rotated on the z fiig gg,%g 5X10 surface of the fabric unt1l the fabrlc failed at WhlCh time 7 D Varp/Fill 60/65 /130 the number of revolutions was noted. 0 W tease-Angle ewes) 45/40 110/108 War Fill 560/540 1,060/1,000 Example XI Abrasiv strength 12,310 23,810

A cotton poplin fabric was treated with a 1% aqueous solution of 1,4-diphenylbenzene as described in Example 75 mnumbel' re/Volume 1.1' Example XIII as described in US. Patent No. 2,786,081. The sectionswere then washed out, the wet crease angle measured. They were dried and dry crease angle, tearing strength and abrasive strength were measured. The results are set forth in the following table:

3. A parchmentized celluloisc textile material of improved crease resistance produced by the process of claim 2.

4. A process as set forth in claim 1 wherein the total dose of ionizing radiation is about 10 to 10 rad.

5. The process of claim 1 wherein the sensitizer is 1,4- diphenylbenzene.

6. The process of claim 1 wherein the sensitizer is anaphthoquinone 1,4-diketo-2,3-dihydro-naphthalene) 7. The process of claim 1 wherein the sensitizer is benzophenone.

8. A process for improving the wet crease resistance and the strength of a cellulosic textile sheet material which comprises subjecting said material to ionizing radiation to a total dose in the range of about 5x10 to 3 x10 rad in the presence of an organic sensitizer in contact with said material which contains molecular groups capable of absorbing said radiation energy and so transferring excitation energy to the cellulosic molecule as to facilitate grafting thereon and applying a graftable organic finishing chemical to the material.

Starting A B o D Material Irradiation Time (hours) 5 1 2 3 Irradiated Dose (rad) 1 x10 215x10 5x10 7.5 1ofl vifiiflififlffffffll so 130 105 160 142 65 130 170 165 150 h vi a gf 660 1, 580 2, 030 1, 990 1, s32

Fill 540 1, 430 2, 110 1, 900 1, 750 Abrasive Strength 12,310 40, 280 63,810 60,210 52,880

1 In number of revolutions. I

9. A process as set forth in claim 8 wherein the cellu- Equivalent results were achieved by substitutmg a 1% 1 I h n osic textile material is irradiated to a total dose between ilgseeggfistiltliszpeilSlOfl of ZlIlC oxide for the 1,4 d1p e yl 11 about 105 n 5x105 I From the above examples it will be apparent that excel- A E i: set if In f e1n the graftlent wet crease resistance can be imparted to a cellulosic i e f fi 9 61111631 15 pp t0 t material fabric without any decrease whatsoever in fiber strength. om a qul In fact fiber Strength appears tube increased 1 1. method as set forth in clalm 10 wherein the liquid The present invention is also applicable to the finishing 15 1 at a temperature f l about 40 a 100 C. of fine fabrics of cotton or regenerated cellulose which l gP as set 1' clalm 3 e m the matehave been subjected to stiffening or transparentizing by IS iP b l 15 of lerated electrons treatment with concentrated sulfuric acid, cupric oxide- 0 i 6 energy e 0W h l 1 I 3 ammonia solution or sodium zincate cellulose solution, as t d l processfas Set 111 Glam 8 hereln accelerwell as to fine fabrics having relatively highly twisted a e 6 9 0 a partlcle energy between about yams Such as voiles and marquisettes and 0.6 mev. are directed at an acute angle to the sur- What is claimed is: fi g zg g t f th l 8 h 1. A process for improving the properties of a cellulosic f me as or W r ll} the textile material of the group consisting of cellulose and 32:32:; orgamc fimshmg Chemlcal 1S a p ymerizable regenerated cellulose textiles, which comprises applying to the textile from dilute aqueous media an organic sensi- 1 lfl s S t fort]: 1It1 512mm 14 wherem h tizer which contains molecular groups capable of absorbymenza e monomer 18 Se ec 6 tom group ing ionizing radiation and transferring excitation energy S1,stmg of acrylates, i 'y es, acrylarnlde, styrene, to the cellulose molecules of said textile selected from vmyl acetate Vmyl q vmyhqene chlonde ethylene the group consisting of diphenyl'benzenes, diphenylmethiz x ggtg g t 11 3 h h ane, triphenylmethane, phenylethanes, fluorene, benzalrafibl if g 1F 1 p 21 fluorene, quinone naphthoquinones, benzoylfiuorenes, beni i 0 game ms mg C emlca 1S a 19 Y- e zil benzalacetophenone, dicinnamylideneacetone, dipheno quinone, hydroxyacetophenone, benzophenone, aniline, 1 2 gigggi t sg ii 11:223 zg the diphenylamine, tributylamine, cyclohexylamine, crotonal- S 111 6 group dehyde citral and mixtures thereof, and subsequently subconslstmg of alcohols aldehydes f Sulfones: jecting the textilewith the sensitizer thereon to ionizing tals halogenated compounds, ammes, s,

radiation to a total dose in the range of about 10 to 10" sistance, tearing strength and abrasive strength produced by the process of claim 1.

phenols, ethylene polymers, acrylic polymers and vinyl polymers.

18. A method as set forth in claim 8 wherein the sensitizer is an unsaturated aliphatic compound of 4 to 20 carbon atoms containing 1 to 3 olefinic unsaturations,

with at least two carbon atoms between plural unsaturations.

19. A method as set forth in claim 18 wherein the unsaturated aliphatic compound is selected from the group consisting of aldehydes, ketones and primary and secondary amines.

20. A method as set forth in claim 8 wherein the sensitizer is an aromatic compound having 1 to 6 benzene rings.

21. A method as set forth in claim 20 wherein the aromatic compound contains two to three uncondensed benzene rings.

22. A method as set forth in claim 21 wherein the aromatic compound is 1,4-dipheny1benzene.

23. A method as set forth in claim 21 wherein the aromatic compound is benzophenone.

24. A method as set forth in claim 20'wherein the aromatic compound contains two to three condensed benzene rings.

25. A method as set forth in claim 24 wherein the aromatic compound is 1,4-naphthoquinone.

26. A finished cellulosic textile fabric of improved wet crease resistance and strength produced by the process of claim 8.

27. A finished fine cellulosic textile fabric of improved wet crease resistance and strength produced by the process of claim 8.

14 28. A method as set forth in claim 14 wherein the polymerizable monomer is acrylamide.

References Cited by the Examiner UNITED STATES PATENTS 2,956,899 10/1960 Cline. 2,986,507 5/1961 Steck. 2,998,329 8/1961 Sovish.

3,001,922 9/1961 Zimm. 3,092,512 6/1963 Magat. 3,097,960 6/1963 Lawton et a1. 3,101,276 8/1963 Hendricks.

FOREIGN PATENTS 758,735 10/1956 Great Britain.

OTHER REFERENCES Blouin, Textile Research Journal, vol. 28, pp. 198-204 (1959).

Gilfillan, Textile Research Journal, vol. 25, pp. 773 777 (1955).

Pan, Textile Research Journal, vol. 29, pp. 415-421 (1959).

J. TRAVIS BROWN, Acting Primary Examiner. 

1. A PROCESS FOR IMPROVING THE PROPERTIES OF A CELLULOSIC TEXTILE MATERIAL OF THE GROUP CONSISTING OF CELLULOSE AND REGENERATED CELLULOSE TEXTILES, WHICH COMPRISES APPLYING TO THE TEXTILE FROM DILUTE AQUEOUS MEDIA AN ORGANIC SENSITIZER WHICH CONTAINS MOLECULAR GROUPS CAPABLE OF ABSORBING IONIZING RADIATION AND TRANSFERRING EXCITATION ENERGY TO THE CELLULOSE MOLECULES OF SAID TEXTILE SELECTED FROM THE GROUP CONSISTING OF DIPHENYLBENZENES, DIPHENYLMETHANE, TRIPHENYLMETHANE, PHENYLETHANES, FLUORENE, BENZALFLUORENE, QUINONE NAPHTHOQUINONES, BENZOYLFLUORENES, BENZIL, BENZALACETOPHENONE, DICINNAMYLIDENEACETONE, DIPHENOQUINONE, HYDROXYACETOPHENONE, BENZOPHENONE, ANILINE, DIPHENYLAMINE, TRIBUTYLAMINE, CYCLOHEXYLAMINE, CROTONALDEHYDE, CITRAL AND MIXTURES THEREOF, AND SUBSEQUENTLY SUBJECTING THE TEXTILE WITH THE SENSITIZER THEREON TO IONIZING RADIATION TO A TOTAL DOSE IN THE RANGE OF ABOUT 10**3 TO 10**7 RAD. 